Yep that included everything!
So see this image:
What’s taking all your time is the glTexSubImage2D call, which is an ancient GL call that should work on about everything, but this should also be happening in vanilla too without GT6 because there’s no GT6 in this callstack at all (glTexSubImage2D is for animated texture, which GT6 has a few of, but the call is still batched quickly so it wouldn’t add much time over normal vanilla if any).
At this point it’s obvious it’s waiting on the driver to respond for 94.4% of the time, whether thats because the driver is slow (which would be odd on this call, it should be a simple transfer to GPU) or it’s called in a loop hundreds of thousands or millions of times.
At this point I’m thinking that something is making that driver call slow (it’s not often used much if at all on modern games, but MC is programmed in a way that was ancient even for MC’s time) and adding GT6, which has a few more animated textures, just compounds it. But that call really shouldn’t be slow on the driver so something is up on your system (something you wouldn’t see affect most of any other games since they don’t use glTexSubImage2D like MC does).
On linux it would be fairly trivial to inspect this, but on windows with its nasty binary blobs I’m not sure how to even start without setting up things that require a lot more knowledge than I could easily pass over a forum post…
My gut instinct is that your GPU is running in a different color mode than MC expects and is making the sub image calls significantly more costly as transforms have to be run, but again, on Windows I’ve no clue how to test or whatever that in an easy way, but that would also be a driver and/or driver setting issue.
EDIT1: It also wouldn’t be an issue if MC did texture animations better as well, but eh, can’t change that. ^.^;
EDIT2: You don’t have anything like rendering injectors (to display overlays in game like chatting apps) or various other things as well?